storefront and woocommerce

Hi,
I’m trying to set up an ecommerce site with storefront theme and woocommerce. Please help with the following questions:
1. how to customise the homepage? my homepage is split into “Shop by category”, “new in” and “best sellers”. I’m starting out with 1 product and don’t need these features yet.
2. When I clicked checkout, I got this error: (404:page not found) or when I click check out with paypal, it gives paypal error (3). how to resolve?
3. Also, footer is aligned left. how to put it in the centre? also, how to change wording in the footer?